You can set up as many users as you like, but there’s a limit to how many users have a licence. 

When a user is given a seat by an administrator, then they are allowed to log in and use The maximum number of users is dependent upon the licences you have purchased. 

If you need more user licences you can upgrade at any time. As an administrator you can check how many user licences are being used and the total you have currently purchased

Click here for more details on how to create new Users